Blower scroll having an aspirator venturi

ABSTRACT

A blower assembly for use with an HVAC module is provided. The blower assembly includes a scroll or volute shaped housing having an air inlet in a wall of the housing for receiving air to be blown by an impeller, and an air outlet from which the blown air passes from the housing. A blower wheel is secured to a rotatable motor-driven shaft extending along a central axis of the air inlet. At least one venture is provided adjacent to the air inlet of the housing, the at least one venturi connectable to an aspirator that is in fluid communication with a sensor unit. Wherein, during operation, the blower wheel pulls air both through the air inlet to the housing and through the at least one venturi.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a blower assembly for use with HVACmodules for passenger vehicles.

2. Description of the Background Art

HVAC modules are used in vehicles to control a passenger compartment airtemperature. The module generally includes a housing having an airinlet, an air blower, an evaporator, a heater core, air outlets, etc.The HVAC module can accordingly either heat or cool air flow from theexterior of the vehicle to the interior of the vehicle, optionally to berecirculated within the vehicle. HVAC modules, including the heatexchangers used for the evaporator and heater core, as well as the airblower and housing are thus known to one skilled in the art.

HVAC modules may be provided with an aspirator which is adapted to pullair over a temperature sensor of a control head. An aspirator part isseparately provided for this purpose and connected to the HVAC module.See, for instance, U.S. Pat. No. 6,347,746 provides an aspiratorconnected to a temperature/humidity sensor, the aspirator beingconnected to the HVAC housing downstream of the blower mechanism,whereby air is drawn from the temperature/humidity sensor to the HVAChousing. See, also, U.S. Pat. No. 6,116,511, which discloses thepresence of an aspirator connected to a temperature sensor, whereby airis drawn from the HVAC housing over the temperature sensor via aventuri.

Aspirators are accordingly generally mounted within a high pressurearea, such that air is moved through a tube that passes by anotheropening which causes suction on the opening. Depending on the locationof the aspirator on the HVAC module, air (hot or cold) may be blown intothe passenger cabin of the vehicle, which is a disadvantage from thestandpoint of controlling the environment of the passenger cabin.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a blowerassembly for use with an HVAC module.

In an embodiment, a blower assembly is provided that includes ascroll-shaped housing, the scroll-shaped housing having an air inlet ina wall of the housing for receiving air to be blown by the impeller, andan air outlet from which the blown air passes from the housing. A blowerwheel is secured to a rotatable motor-driven shaft, the shaft extendingalong a central axis of the air inlet of the housing. At least oneventuri is provided and is adjacent to the air inlet of the housing andis in fluid communication with a sensor unit, whereby, in operation, theblower wheel pulls air both through the air inlet to the housing andthrough the at least one venturi.

Further, scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus, are not limitiveof the present invention, and wherein:

FIG. 1 is a view in perspective of a blower assembly according to anembodiment of the present invention;

FIG. 2 is a top view of the blower assembly;

FIG. 3 is a view in perspective of an embodiment of a blower wheel foruse in the present invention;

FIG. 4 is a cross-sectional view of the blower assembly of the presentinvention depicting a chamber having a circumferential venturi opening;

FIG. 5 is a cross-sectional view of a conventional blower assembly asviewed from the side;

FIG. 6 is a cross-sectional view of the blower assembly of the presentinvention as viewed from the top depicting a single venturi embodiment;

FIG. 7 is a cross-sectional view of the blower assembly of the presentinvention depicting a multiple venturi embodiment;

FIG. 8 is a bottom view of the upper housing of the embodiment of FIG. 1depicting a circumferential venturi embodiment;

FIG. 9 is a top view of the upper housing embodiment of FIG. 10depicting a multiple venturi embodiment; and

FIG. 10 is a view in perspective of the blower assembly of the presentinvention having multiple venturis.

DETAILED DESCRIPTION

The blower assembly of the present invention will be described furtherbelow in conjunction with the Figures.

The blower assembly of the present invention comprises a portion of anHVAC module of a passenger vehicle. The HVAC module conditions outsideair blown into the interior of the vehicle for purposes of heating,cooling or ventilation of the vehicle interior. The module accordinglyheats or cools and distributes air within the interior of the vehicle.Such modules are also connected to various sensors, such as temperatureor humidity sensors. The interior of the HVAC module is in fluidcommunication with the temperature or humidity sensor housing. Thedesigns of such HVAC modules are well known to those skilled in the art.

The blower assembly 1 of the present invention which comprises a portionof an HVAC module is shown in FIG. 1 as having a volute or scroll-shapedhousing 3. The housing 3 has an air inlet 5 and an air outlet 7, wherebymultiple air inlets or air outlets can be provided. The housing may beformed, for example, by securing together mating sides to form thehousing.

The blower assembly 1 has a blower wheel 9 secured to a rotatingmotor-driven shaft 11. The shaft extends along a central axis of inlet 5in the housing.

The scroll-shaped housing 3 has an axial air inlet 5 in a side wall 15of the housing. The air inlet 5 provides air to be blown by the blowerwheel 9. The housing 3 also has an air outlet 7 through which the blownair passes from the housing in a generally tangential manner.

In accordance with an embodiment of the present invention, at least oneventuri is provided at a position adjacent to the air inlet 5, with theat least one venturi connected to an aspirator tube in communicationwith a sensor, such as a temperature sensor.

In one embodiment, as depicted in FIG. 1, a separate outer air chamber17 is circumferentially positioned about the air inlet 5. The outer airchamber 17 has an air inlet 19 connected to an aspirator 21, and atleast one air outlet in the chamber comprising at least one venturiopening 25 adjacent the air inlet 5. The aspirator 21 is in fluidcommunication with a sensor, such as a temperature sensor (not shown).Chamber 17 may have multiple venturi openings 25 spaced about thecircumference of the air inlet 5 as shown in FIG. 9. Alternatively, theventuri opening 25 may comprise an annular opening extending about thecircumference of the air inlet 5 as shown in FIGS. 4 and 8. Multipleaspirators may also be employed connected both to the sensor as well asbeing spaced about the circumference of the air inlet 5 as shown in FIG.10. The particular design of the venturi opening is not critical topractice of the present invention, with the exception that the venturiopening be positioned sufficiently close to the perimeter of the airinlet 5 for the desired venturi effect to be achieved. The venturiopening(s) are of sufficient dimension to provide the desired rate ofair flow across the sensor. Also, while air inlet 5 is shown to becircular, it may be of any suitable geometric configuration whichpermits sufficient air flow into the housing.

The blower wheel 9 may be of any suitable configuration. Preferably, asdepicted in FIG. 3, the blower wheel comprises a centrifugal blowerimpeller having a central hub 27 mounted on the rotating motor-drivenshaft 11. The impeller has a central conical section 13 extendingdownwardly and outwardly from the central hub and terminating at anouter circumferential edge 29. Impeller blades 31 extend upwardly fromthe edge 29, terminating at circumferential rim 33. The blades mayeither be restrictedly confined by the circumferential rim 33 such thatthe ends of the blades may move within the rim, or the ends of theblades may be fixed to the rim. The blades can be inclined with respectto each other such that air is caused to be drawn into the housing uponrotation of the blades on shaft 11. The blower wheel (and impellers) maybe of any suitable configuration which permits air to be drawn into thehousing and forced out of the housing as discussed above. One ofordinary skill in the art can readily arrive at a suitable configurationfor the blower wheel and impellers.

The shaft 11 is driven by a suitable motor, which motor is generallyplaced within the housing adjacent the end of the shaft. The motor canbe connectable to a speed control unit for controlling the motor and/ora speed of the motor.

In operation, when driven by the associated motor, motor-driven shaft 11causes the blower wheel to rotate at a pre-selected speed. Upon rotationof the blower wheel, air is caused to be drawn axially into air inlet 5.Air is accordingly also drawn into the venturi opening 25 via theaspirator 21. Air drawn into the housing is then forced radiallyoutwardly between the blower and the interior of the housing, ultimatelyexiting tangentially through outlet 7 of the housing.

As the air is caused to pass over an evaporator core (not shown)associated with the HVAC module, heat is removed from the air passingover the core. Also, as air is caused to pass over a heater coreassociated with the HVAC housing, heat is added to the air passing overthe core. Various other modes may be employed, such as a control door tocontrol a mix of hot and cold air to result in a desired vehicleinterior temperature. In addition, various temperature sensors may beemployed at various locations in the HVAC module in connection withvarious climate control strategies. The blower housing is thus in fluidcommunication with a source of exterior air as well as with the interiorof the vehicle for circulating outside air into the interior, or forrecirculating air within the vehicle in a recirculation mode.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are to beincluded within the scope of the following claims.

1. A blower assembly for use with an HVAC module, the blower assemblycomprising: a scroll or volute shaped housing, the housing having an airinlet in a wall of the housing configured to receive air to be blown byan impeller, and an air outlet from which the blown air passes from thehousing; a blower wheel secured to a rotatable motor-driven shaftextending along a central axis of the air inlet; and at least oneventuri adjacent to the air inlet of the housing, the at least oneventuri connectable to an aspirator that is in fluid communication witha sensor unit, wherein, during operation, the blower wheel pulls airboth through the air inlet to the housing and through the at least oneventuri.
 2. The blower assembly according to claim 1, further comprisinga separate outer air chamber circumferentially positioned about the airinlet, the outer air chamber having an inlet connected to an aspirator.3. The blower assembly according to claim 2, wherein the venturicomprises a circumferential slit in the outer air chamber adjacent theair inlet.
 4. The blower assembly according to claim 2, wherein theouter air chamber includes multiple venturis adjacent to the air inlet.5. The blower assembly according to claim 1, comprising a single venturilocated adjacent to the air inlet.
 6. The blower assembly according toclaim 1, comprising multiple venturis located adjacent to the air inlet,each being connected to a different aspirator.